SCHEDULE 13D/A 0001545806 XXXXXXXX LIVE 7 Ordinary Shares, par value US$0.0001 per share 09/30/2025 false 0001962738 G1933S101 CASI Pharmaceuticals, Inc.

1701-1702, CHINA CENTRAL OFFICE TOWER 1 NO. 81 JIANGUO ROAD, CHAOYANG DISTRICT BEIJING F4 100025

Chi Sing Ho 852-3903 1333 IDG Capital Management (HK) Company Ltd 99 Queen's Road, Central Hong Kong K3 00000 0001508829 IDG-Accel China Growth Fund III L.P. WC E9 855222 60628 855222 60628 915850 N 4.5 PN The value in lines 7 and 9 represents 855,222 ordinary shares of the Issuer held by the Reporting Person. The value in lines 8 and 10 represents 60,628 ordinary shares of the Issuer held by IDG-Accel China III Investors L.P. ("IDG-Accel Investors"). Percent of Class Represented by Amount in Row (11) is based on 20,548,273 ordinary shares of the Issuer outstanding as of September 30, 2025, as disclosed in the Issuer's current report on Form 6-K filed with the Securities and Exchange Commission on November 14, 2025. 0001550193 IDG-Accel China III Investors L.P. WC E9 60628 855222 60628 855222 915850 N 4.5 PN The value in lines 7 and 9 represents 60,628 ordinary shares of the Issuer held by the Reporting Person. The value in lines 8 and 10 represents 855,222 ordinary shares of the Issuer held by IDG-Accel China Growth Fund III L.P. ("IDG-Accel Growth"). Percent of Class Represented by Amount in Row (11) is based on 20,548,273 ordinary shares of the Issuer outstanding as of September 30, 2025, as disclosed in the Issuer's current report on Form 6-K filed with the Securities and Exchange Commission on November 14, 2025. 0001550192 IDG-Accel China Growth Fund III Associates L.P. AF E9 855222 60628 855222 60628 915850 N 4.5 PN The value in lines 7 and 9 represents 855,222 ordinary shares of the Issuer held by IDG-Accel Growth. The Reporting Person is the sole general partner of IDG-Accel Growth. By virtue of this affiliation, the Reporting Person may be deemed to have sole voting and dispositive power with respect to all these securities. The value in lines 8 and 10 represents 60,628 ordinary shares of the Issuer held by IDG-Accel Investors. The Reporting Person has the same general partner, IDG-Accel China Growth Fund GP III Associates Ltd. as IDG-Accel Investors. By virtue of this affiliation, the Reporting Person may be deemed to be under common control with IDG-Accel Investors and thus share voting and dispositive power with respect to these shares. Percent of Class Represented by Amount in Row (11) is based on 20,548,273 ordinary shares of the Issuer outstanding as of September 30, 2025, as disclosed in the Issuer's current report on Form 6-K filed with the Securities and Exchange Commission on November 14, 2025. 0001564281 IDG-Accel China Growth Fund GP III Associates Ltd. AF E9 915850 0 915850 0 915850 N 4.5 CO The value in lines 7 and 9 represents (i) 855,222 ordinary shares of the Issuer held by IDG-Accel Growth; and (ii) 60,628 ordinary shares of the Issuer held by IDG-Accel Investors. The Reporting Person is the ultimate general partner of both IDG-Accel Growth and IDG-Accel Investors. By virtue of this affiliation, the Reporting Person may be deemed to have voting and dispositive power with respect to all these shares. Percent of Class Represented by Amount in Row (11) is based on 20,548,273 ordinary shares of the Issuer outstanding as of September 30, 2025, as disclosed in the Issuer's current report on Form 6-K filed with the Securities and Exchange Commission on November 14, 2025. 0001545806 Ho Chi Sing AF Z4 0 915850 0 915850 915850 N 4.5 IN The value in lines 8 and 10 represents (i) 855,222 ordinary shares of the Issuer held by IDG-Accel Growth; and (ii) 60,628 ordinary shares of the Issuer held by IDG-Accel Investors. The Reporting Person and Quan Zhou are directors and shareholders of IDG-Accel China Growth Fund GP III Associates Ltd., the ultimate general partner of IDG-Accel Growth and IDG-Accel Investors, thus may be deemed to share voting and dispositive power with respect to all these shares. Percent of Class Represented by Amount in Row (11) is based on 20,548,273 ordinary shares of the Issuer outstanding as of September 30, 2025, as disclosed in the Issuer's current report on Form 6-K filed with the Securities and Exchange Commission on November 14, 2025. 0001491503 Zhou Quan AF X1 76788 915850 76788 915850 992638 N 4.8 IN The value in lines 7 and 9 represents 76,788 ordinary shares of the Issuer issuable upon exercise of certain options issued by the Issuer to Quan Zhou. The value in lines 8 and 10 represents (i) 855,222 ordinary shares of the Issuer held by IDG-Accel Growth; and (ii) 60,628 ordinary shares of the Issuer held by IDG-Accel Investors. The Reporting Person and Chi Sing Ho are directors and shareholders of IDG-Accel China Growth Fund GP III Associates Ltd., the ultimate general partner of IDG-Accel Growth and IDG-Accel Investors, thus may be deemed to share voting and dispositive power with respect to all these shares. Percent of Class Represented by Amount in Row (11) is based on 20,548,273 ordinary shares of the Issuer outstanding as of September 30, 2025, as disclosed in the Issuer's current report on Form 6-K filed with the Securities and Exchange Commission on November 14, 2025. Ordinary Shares, par value US$0.0001 per share CASI Pharmaceuticals, Inc. 1701-1702, CHINA CENTRAL OFFICE TOWER 1 NO. 81 JIANGUO ROAD, CHAOYANG DISTRICT BEIJING F4 100025 This Amendment No. 7 amends the Statement on Schedule 13D dated January 30, 2012 as amended by Amendment No. 1 dated February 2, 2012, Amendment No. 2 dated June 11, 2012, Amendment No. 3 dated March 6, 2013, Amendment No. 4 dated March 20, 2018, Amendment No. 5 dated February 21, 2023 and Amendment No. 6 dated February 3, 2025 (as so amended, the "Original Schedule 13D") and is being filed to reflect changes in the percentage of Ordinary Shares beneficially owned by the Reporting Persons due to increase in the amount of total issued and outstanding Ordinary Shares of the Issuer over time. Except as amended and supplemented herein, the information set forth in the Original Schedule 13D remains unchanged. Capitalized terms used herein have meanings as assigned thereto in the Original Schedule 13D, unless defined herein. Item 5(a) of the Original Schedule 13D is hereby amended and restated in its entirety as follows: The aggregate number and percentage of the Ordinary Shares beneficially owned by each Reporting Person is set forth on the cover pages to this Statement on Schedule 13D and is incorporated by reference herein. The ownership percentage appearing on such pages has been calculated based on a total of 20,548,273 Ordinary Shares of the Issuer outstanding as of September 30, 2025, as disclosed in the Issuer's current report on Form 6-K filed with the Securities and Exchange Commission on November 14, 2025. The Reporting Persons disclaim membership in any "group" with any person other than the Reporting Persons. The filing of this Statement on Schedule 13D by the Reporting Persons shall not be considered an admission that such Reporting Persons, for the purpose of Section 13(d) of the Exchange Act, are the beneficial owners of any of the Ordinary Shares covered in this Statement on Schedule 13D, and the Reporting Persons expressly disclaim such beneficial ownership. Item 5(b) of the Original Schedule 13D is hereby amended and restated in its entirety as follows: For each Reporting Person, the number of the Ordinary Shares as to which there is sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition are set forth on the cover pages to this Statement on Schedule 13D, and are incorporated herein by reference. Item 5(c) of the Original Schedule 13D is hereby amended and restated in its entirety as follows: None of the Reporting Persons has engaged in any transactions in the Issuer's securities during the past sixty days other than as disclosed herein. Item 5(e) of the Original Schedule 13D is hereby amended and restated in its entirety as follows: Each of the Reporting Persons ceased to be the beneficial owner of more than five percent of the Ordinary Shares of the Issuer on September 30, 2025. IDG-Accel China Growth Fund III L.P. /s/ Chi Sing Ho on behalf of IDG-Accel China Growth Fund GP III Associates Ltd., ultimate General Partner of IDG-Accel China Growth Fund III L.P. 01/20/2026 IDG-Accel China III Investors L.P. /s/ Chi Sing Ho on behalf of IDG-Accel China Growth Fund GP III Associates Ltd., General Partner of IDG-Accel China III Investors L.P. 01/20/2026 IDG-Accel China Growth Fund III Associates L.P. /s/ Chi Sing Ho on behalf of IDG-Accel China Growth Fund GP III Associates Ltd., General Partner of IDG-Accel China Growth Fund III Associates L.P. 01/20/2026 IDG-Accel China Growth Fund GP III Associates Ltd. /s/ Chi Sing Ho 01/20/2026 Ho Chi Sing /s/ Ho Chi Sing 01/20/2026 Zhou Quan /s/ Quan Zhou 01/20/2026